Section 20112 Of Article 2. Proration From California Probate Code >> Division 10. >> Chapter 1. >> Article 2.

. (a) In making a proration of the federal estate tax, allowances shall be made for credits allowed for state or foreign death taxes in determining the federal tax payable and for exemptions and deductions allowed for the purpose of determining the taxable estate.
  (b) In making a proration of the California estate tax, allowances shall be made for (1) credits (other than the credit for state death taxes paid) allowed by the federal estate tax law and attributable to property located in this state, and (2) exemptions and deductions allowed by the federal estate tax law for the purpose of determining the taxable estate attributable to property located in this state.
  (c) In making a proration of an estate tax, interest on extension of taxes and interest and penalties on any deficiency shall be charged to equitably reflect the benefits and burdens of the extension or deficiency and of any tax deductions associated with the interest and penalties.